Operating mechanism for fuel-pumps of internal-combustion engines.



A. W. THOMPSON. OPERATING MECHANISM FOR FUEL PUMP S or iNTEHNAL nnmnusnou ENGINES.

APPLICATION FILED JUNE 4. l9l8. V

Patented Apr. 1,1919.

2 SHEETS-SHEET I INVEHTOII', .Hrthur B I f 4 "URI/EV WI INESS A. w. THOMPSON. OPERATING MECHANISM FOR FUEL PUMPS OF INTERNAL COMBUSTION ENGINES.

APPLICATION HILED JUNE 4.1918

Patented Apr. 1.1919;

2' SHEETS-SHEET 2.

IIIII W MVM W QAQAAWD% W L W/ I IIQ I. I III II-HHII I mmlmn firthur wThomks'an w/mss A TTORNE V ARTHUR w. THOMPSON, or OTTAWA, ONTARIO, cnmne.

OPERATING MECHANISM FOR FUEL-PUMPS 01: INTERNAL-CQMBUSTION ENGINES.

Specification of Letters Patent.

Patented Apr. 1, 1919.

Application filed June 4, 1918. Serial 110.2383.

T0 (ill whom it may concern Be it known that I, Airruun IV. THOMP- sox', a citizen of the Dominion of Canada, and a resident of the city of Ottawa. Province of Ontario, Dominion of Canada, have invented certain new and useful Improvm m'ents in Operating Mechanismsfor Fuel- Pumps of Iuternal-Conibustion Engines, of which the following is a specification. I

This invention is an improved operating mechanism for fuel pumps of internal oomhustion engines of that type in which the necessary quantity of liquit fuel is forcibly injected into the successive compressed air charges to make up the explosive mixture. The injection of the liquid fuel is ordinarily effected by means of a small force livcring a fraction of a drop or a cw t rops of liquid. depending upon the size of the engine. the injection preferably taking place directly into the cylinder. although it may take place into the compressed air charge he fore' the delivery of the latter to the explosion chamber. My invention relates solely to the operating and controlling mechanism for the pump and is particularly adapted for two-cycle engines. although hy suitable altcrationhit may he adapted to a four-cycle engine.

Among the important ohjcctsof my invention are to operate the fuel pump hy means of the compression and raretication'of the air in the crank case snitu-hly controlled so as to give a quick and forceful injection of the, .fliel to automatically or manually time the injection in relation to the compression stroke, of the engine piston: and to regulate the amount of fuel injected.

Mv improved mechanism includes a free floating air piston forced in ()llttlit'tt'llflt! hy the compression otF-air in the engine crank case and returned to deliver, a pneumatic. hammer hlow on the fuel pump plunger hv the rarclication ofair inthe engine cran case. By means of 'niy iiu iroyed construction-I am ahle to regulate tile stroke of this air piston.'tl|-e time of its rcturn'or power-' 1pump depreferred embodiment thereof in the accompanying drawings to which reference is to be had. In these drawings I have illustrated, somewhatconventionally, a two-c 'cle internal combustion engine, but it wil of course he understood that such engine forms no portion of my invention and that: my invention ma y he applied to other types of engines and in various different ways and positions.

In these drawings:

Figure 1 is a side elevation of an engine provided with my improved fuelrpump operatingand controlling mechanism, and

Fig. 2 is a central vertical section through said mechanism on a very much larger scale.

I have illustrated my invention as applied [on twoc vclc engine havin a water ]ackctcd cylinder 10 and a eran: case 11. The water may be withdrawn from the upper part of the water jacketthrough a pipe 12. and forced by a pump 13 through a pipe 14 to a. cooler 15, from which it may returnthrough a conduit 16 to the water jacket. The pump is shown in the supply from the'jacket to the cooler hut this is immaterial as the ump may be in the conduit 16 from the coo er to the jacket. or in some cases. a thermo-cycle.

may he utilized and the pump eliminated or the jacket mayIhe air cooled.

The air is taken into the crank'case through any suitable form of inlet 17, which may have a throttle or other controllin i-ueans and an automatic non rcturn cheet valve or as shown in the drawing, may he uncovered by the piston at the upper end of its upstroke to permit the inrush of air to the crank case. At the beginning of the dmvnstroke the piston covers port 17 and when near the end of the downstroke it uncovers an exhaust port :21 and finally uncovers a passage :42. conneetinnthe crank case with the working or explosive chamber The fuel pump :24 ta es liquid fuel from any suitable source of supply aml delivers it through a conduitzlfi through an injector 26, prefcrahly in the cylinder head. I do not wish to he limited to-any particular form of injector but I preferably employ the const ructiou shown in my prior Patent 1.223.194 issued April 17. 1917. This oil pump '24 is of such a size that upon each downstroke of the. plunger 27 thereof a suliicieut amount of liquid fuel is delivered through the. onduit 25 to unite with the air in the chamher '23 aad form the explosive mixture. The pinup plunger 27 is normally forced up to its limitmg position by a spring 27 until a collar or flange 29 thereon engages with a stop 30, here shown as a bracket, for guiding the pump plunger. As previously stated my invention resides solely in the mea s for operating this pump plunger at the esired time intervals and to the desired extent to pro erly deliver the liquid fuel and controlt e operation of the engine.

In the specific form of my invention illustrated, I employ an air chamber in g the form of a cylinder and having a free floating reciprocatory or vibratory member therein in the form of a piston 36. Th one end of the cylinder has a passage or conduit 37 connecting it with the interior of the engine crank case so that the portion of the chamber beneath the piston is at all times subject to the as pressure variations in the crank case. T e piston has a rod or striker member 38, suitably guided in the lower cylinder head 39 and substantially in alinement with the pump plunger 27. The upper cylinder head 40 has a tube or sleeve 41 in alinement with the upper end of the rod 38 and of a size to receive and fit the latter sufficiently closely to prevent any rapid escape of air therebetween when the upper end of the rod is within the tube. This upper endof the rod has a socket in its upper end receiving a ball valve 42 held against removal by a retainer 43. Below the valve there is an air passage 44 leading from the valve seat out through one side of the rod above the iston."

I The cylinder head 40 also has an inwardly opening ball valve 45 pressed upwardly against its seat by a coil spring 47. To facilitate the read adjustment of the tension of thisv sprin ;t e valve seat is formed in a collar or tin ling 47 screw threaded into a cup 48 against the bottom of which seats the spring. By rotating the collar 47 the valve seat and the sprin support may be brought toward or away rom each other to increase or decrease thesprin g tension.

Thetu be 41 is slidable endwise within the cylinder head and may, if desired, be locked or clam ed in the desired adjusted position. A sim e form of holding means includes a sleeve 9 integral or rigid with the cylinder head and slotted lengthwise at its upper free end. A nut 50 having a taper thread enaging this slotted sleeve may be used to si htly collapse the sleeve and clamp the in with any desired degree of pressure and with the tube in any desired endwise ad'ustment.

.y mpro'ved device so far as described,

operates substantially as follows: The en gine piston in reciprocating operates to compress air in the engine base durmg the er:- plosioii stroke of the engine piston and this mnunressed air mav flow through the connection 37 and opera te are iindi'zside of the piston 36 to raise the utter together with its rod 38. After the rolongation or upper extension of the rod' 8 enters the tube 41 there is no escape for the air above thepiston except through the passage 44, the air operating to raise the check valve 42 and escape to the atmosphere through the open end of the piston rod and tube 41. The check valve is prevented from moving from its seat to more than a slight extent by the retainer 43. It will, of course, be obvious that if the cylinder 35 has its axis horizontal rather than vertical or if it be inverted, a spring or suitable means would be used to hold the valve to its seat whereas gravity accomplishes this result when the parts are inthe position illustrated. The constriction of the flow of air ,past the check valve 42 decreases the velocity of the iston until the passage 44 comes within an is covered by the tube 41. The piston is then brought to rest as the air above it cannot escape. When the engine piston reaches the upper end of its stroke and the gas pressure in the crank case is released, the piston 36 is held suspended as the air cannot gain access to the air chamber above the iston. As the engine piston starts up on its compression stroke, there is a corresponding rarefication of the air in the crankcase. When this rarefication is sufficient to overcome the action of the spring 46, holding the check valve 45 to itsseat, the said check valve will open and air will enter above the piston 36 and permit the downward movement of the latter. Duri a position that air may enter the cylinder through the tube without passing the check valve 42. The further downward movement of the piston 36 will be very rapid iis air may freely enter above the piston and the piston will be drawn down not only by the suction from the crank case but by the action of gravity until the lower end of the piston rod strikes a hammer blow on the upper end of the pump pluinger rod. By varymg the tension of the,sprin"g 46, the air rarefication necessar td openthe valve and permit the start of tile ownward movement of the piston 36 me be varied at will. Thus the ti-min of the uel delivery may be con trolled. he tube 41 being adjustable may release the piston for a longer or shorter free-stroke and as the Ian h of this stroke will control its force, the l) ow on the piston rod and theconsequent quantity of oil de-' livered by the force pump ma be varied.-

weight of t 0 piston and "the coriseq11ent force of the blow.

Although the tube 41 may be adjusted b,

hand to vary the free stroke and the consequent quantity of fuel delivered, I may, if

desired, adjust this tube endwise in accordance with the speed of the engine so as to give an automatic governor, By moving the tube inwardly as the speed ofthe engine increases, the quantity of fuel delivered for each stroke may be correspondingly reduced and the speed held down to the proper limit.

Various different means may be provided for efl'ecting this automatic adjustment of the tube 41. Merely as one example of such means, Ihaveshown a jacket water cylinder 52 with a piston 53 therein rigidly secured to a'stationary part of the'engine. 'The lower end of the cylinder is connected by a bracket 54 to the upper end of the tube 41 and. the lower end of the cylinder is connected by a flexible tube 55 to the outlet of the water circulating pump. The cylinder may have a coil spring 56 between the up er surface thereof and an ad ustable cylinc er head 57 so as to noi'mally'lift the cylinder 52 and pull up the tube to the desired extent for engine idling. The tension of this spring .may be varied by rotating the cylinder head 57 and thereby varying the'position of the stop for the upper end of the spring. As the engine-speed increases, the water pressure in the tube 55 will increase and the pressure in the cylinder 52 will force the latter down against the action of the spring 56 and force the tube 41 into the cylinder 35th a corresponding extent. Instead of having the hydraulic controlling means operating from the jacket water )ump, a centrifugal ball governor or-any ot 1e1- governing means may be employed for, properly adjusting the i051- tion of the tube 41 and the time in the own stroke of the piston 36 when the air will be freely admitted and the pneumatic hammer blow begun I 7 Various chun cs, alterations, substitutions, and reversals 0 parts may be eil'ected Will]- out departing from the essential novelty or maicrially affecting the operation of the dcvicca ()tlicrkinds of check valves than those 7 shown may be employed. The upper end of the piston rod may constitute a tube tclescoping on tbe uljnstable rod carriedvby the cylinder head or a weighted diaphragm may be omploycd instead of the piston r a il spring may act instead of or together with the gravity in aiding the striking blow of the pneumatic o 'icrated member Other means.

might be employed for controlling the flow of air to and from the cylindcr. In those engines in which thecrank case is not used for compression purposes, any other portion oftlic engine serving this fnnciionor a specinl air compressor operated from the'cngine may provide the nccessarypressurcvariations fol-operating;thc device. a

Having thus described my invention. what I claim as new and hers Patent ie- A 1. Thecombination with an internal combustion engine and a'fuelfeed pump therefor provided with a reciprocatory plunger, of a cylinder a free floating piston therein, and pneumatic connectionslbetween said engine and said cylinder for effecting the reciprocation of said hammer blows to said plunger.

2. The combination with an internal coinbu'stion engine, of an air chamber, a mem ber therein mounted for to-and-fro movement, connections between said chamber and the crank caseof theen inc for eifecting the movement of said'menr )er by variations in gas pressure of said case, and a fuel fecd pump) having a plunger separate from said inem i 3. The combination ofan internal conibnstion engine, ofa member having a toand-fro movement effected by gas pressure variations in the engine crank case, a p u|np having a plunger separate from but in the path of movement of said member, and means for controlling the gnoycment of sa id member whereby it intermittently delivers hamnciblows tosaid plunger.

4. The combination with an internal comrylindcr having pcrmancntly' open connections to the crankcase of said on ine, a free floating piston within said cy under and adapted to deliver hannncr blows to said plunger, and means for controlling the How of air to and from said cylin-dcr at the side ofthe piston opposite to said crank case connection.

1 The combination with anintcrnal colubustion engine and a fuel food pump there for provided with a reciprocatory plungcigof an air chamber, a free flouting piston therein adapted to opcrativcly cngagesaid plunger,

permanently open connections bi-twccn said chamber and the engine clrank case, a valve controlled air outlet at the op -iosltc side of said, pistoma valve controlled air inlet, and

means for controlling one of s'aid valves.

7. A fuel feed pump operat ng mechanism including a cylind'cr-havlng one and adapted to be connected to an engine crank case and the opposite .end of said cylinder, means for piston and delivery of.

er and operated by the latter during i portion only of the movement-of said mclnwith an internal conr.

desireto secure asLet- 'aispring pressed inwardly operating valve at" regulating the tension of the spring thereof,

l cylinder to the atmosphere when said pisin, adjustable cooperating means on said ton has been moved to a predetermined 'ex: tent by crank case vacuum.

9. A fuel feed pump operating mechanism including a cylinder, at piston'disposed therecy inder and piston for opening and closing one end of the cylinder to the atmosphere,

and an independent valve controlled air inlet to said cylinder on the same side of the piston.

10. The combination with an internal combustion engine, and a reciprocatory fuel feed pump therefor, of a cylinder having one end in open communication with the en gine crank case, a piston within said cylin' der separate from said pump, and means whereby the movement of said piston in one direction is limited during the compression of air in the crank case and the time of the i return movement of said piston under the feed pump therefor, end in open communication with the engine I piston influence of crank case vacuum for pump operation is controlled.

l1. The combination with an internal combustion engine, anda reciprocatory fuel of a. cylinder having one crank case, a piston within said cylinder, and means whereby the movement of said in one direction independent of said is limited during the compression of pum and the speed and air in the crank case,

. force of the return movement of said piston under the influence of crank case vacuoration is controlled.

ination with an internal and a reciprocatory feed a piston thereum for pump 0 12. The com combustion engine, pump therefor, of a cylinder,

in, connections for moving said piston in one direction upon crank case compression and in .the opposite direction by crank case vacuum to operate the pump,

combustion engine, and a reciprocatory and m ans timing the release of the piston or said last-mentioned stroke.

18:-The combination with an internal feed for i 1n connections one direction upon crank case compression direction by crank case vacuum to operate the pump,'anda tube having telescoping relations to said iston and ad'ustable endwise for timing t e reand in the opposite lease 0 the piston for said last mentioned.

stroke.

14. A fuel feed pum operating mechanism for internal com ustibn engines including a cylinder, a piston "movable therein on variations in crank case s pressure, a projection on. said piston, an

der and telesco ing with said projection to control the in ow of air to said cylinder and the release of said piston for free movement under crank case vacuum.

for moving said piston in a tube adustable lengthwise in respect to said cylin-- 15. The combination of an internal oombastion engine and a reciprocal fuel feed pump therefor, of a cylinder and piston communicating with the crank case so that the said piston is moved in one direction upon crank case compression and in the opposite direction upon crank case rarefication, to operate the pump and means for timing the release of the piston from its air sealed position for said last mentioned stroke.

16. The combination of an internal combustion engine and a reciprocal fuel feed pump therefor, of a cylinder and piston communicating with the crank cases .so that the said piston is moved in onedirection upon crank case compression and in the opposite direction upon crank case rarefication to operate the pump, a; tube having 138188201):- ing relations to said piston and adjustably endwisejor regulating the length of the said last mentioned stroke.

17. A fuel feed pump mechanism for internal combustion en ines, including :1 cylinder, a piston movab e'therein on variations in crank case pressure, piston and a tube adjustable lengthwise in respect to said cylinder and telescoping with said projection to control the outflow and inflow of air to said cylinder forming an air seal to hold the piston at rest or to allow the release of said piston for under crank case vacuum.

Signed at Clayton, in the count ferson and State of of May, A. D; 1918.

of Jefa pro ection on said free movement New York, this 31 day 4 

